Fix broken links 6

We have a number of broken links in the docs. Many of which will hopefully be fairly straightforward to fix (they are already redirecting to the new URL).

We should take the time to validate the redirects and update the links:

  public/ee/user/infrastructure/clusters/connect/new_civo_cluster.html:
    [ ERROR ] external_links - broken reference to https://civo.com/signup: link has moved permanently to 'https://www.civo.com/signup'
    [ ERROR ] external_links - broken reference to https://www.civo.com/account/security: link has moved permanently to 'https://dashboard.civo.com/security'
    [ ERROR ] external_links - broken reference to https://www.civo.com/account/kubernetes: link has moved permanently to 'https://dashboard.civo.com/kubernetes'
  public/ee/user/infrastructure/iac/terraform_state.html:
    [ ERROR ] external_links - broken reference to https://www.terraform.io/language/settings/backends: link has moved permanently to 'https://www.terraform.io/language/settings/backends/configuration'
    [ ERROR ] external_links - broken reference to https://www.terraform.io/docs/language/settings/backends/http.html: link has moved permanently to 'https://www.terraform.io/language/settings/backends/http'
  public/ee/user/infrastructure/iac/troubleshooting.html:
    [ ERROR ] external_links - broken reference to https://www.terraform.io/docs/language/settings/backends/http.html: link has moved permanently to 'https://www.terraform.io/language/settings/backends/http'
  public/ee/user/project/clusters/add_gke_clusters.html:
    [ ERROR ] external_links - broken reference to https://cloud.google.com/kubernetes-engine/docs/quickstart: link has moved permanently to 'https://cloud.google.com/kubernetes-engine/docs/deploy-app-cluster'
  public/ee/user/project/import/github.html:
    [ ERROR ] external_links - broken reference to https://docs.github.com/en/rest/reference/users: link has moved permanently to 'https://docs.github.com/en/rest/users'
    [ ERROR ] external_links - broken reference to https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-github-user-account/managing-email-preferences/setting-your-commit-email-address: link has moved permanently to 'https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-personal-account-on-github/managing-email-preferences/setting-your-commit-email-address'
  public/ee/user/project/integrations/servicenow.html:
    [ ERROR ] external_links - broken reference to https://docs.servicenow.com/bundle/orlando-servicenow-platform/page/administer/integrationhub-store-spokes/concept/gitlab-spoke.html: link has moved permanently to 'https://docs.servicenow.com:443/bundle/sandiego-servicenow-platform/'

See: #368300